Presently, paystation telephone systems are manufactured and produced to operate in a regulated line or coin line environment or in a customer owned, coin operated telephone (COCOT), e.g. business line environment. Paystations operable in the coin line mode are generally controlled via a central office through the use of the telephone line ring/tip pair and a ground line. The Bell operating companies are examples of a regulated system which control numerous paystations throughout the United States. In contrast, the COCOT systems are produced for individual owners who maintain, service and operate the COCOT paystations as a business for profit. COCOT paystations include a microprocessor providing the intelligence to operate the paystation. Programs are stored in the microprocessor's memory for carrying out the features of the paystation. However, once conventional COCOT telephones are installed in the field, the owner cannot change any functional operations of the paystation but rather can only affect certain paystation characteristics such as calling rates, etc.
Because each system is controlled differently, vendors supplying paystations to regulated companies and individual customers currently produce either two separate paystation telephone units or a single unit which requires the removal and insertion of circuit cards in order to change the operation from a coin line telephone to a COCOT telephone. The use of two separate paystations has the disadvantages of not allowing the paystations to be interchanged and increases a manufacturers overall cost due to the necessity of carrying two distinct product lines. Similarly, requiring a change of circuit cards is disadvantageous because it increases the time and labor costs associated with servicing the phones installed in the field. These problems arise because each system is controlled differently--coin line systems by a central office and COCOT systems by the paystation itself. It has heretofore been unable for vendors to integrate such systems due to their individual control and operating characteristics. For example, the paystation telephone must operate differently to carry out such features as voice messaging, charging for incoming calls, coin tone fraud prevention, safety checks, coin disposal (how the paystation collects and refunds), dialing sequence (whether the paystation passes the digits dialed directly to the telephone line or buffers the digits and then sends them to the telephone line), voice prompts (where the paystation voices a message to the paystation user), and the like, when controlled via the central office in the regulated system or when controlled via the microprocessor contained within the paystation in a COCOT system.
There is therefore needed a paystation telephone system that integrates both a COCOT and a coin line system, without requiring hardware modifications, and provides a wide range of paystation features operable in either mode.